CN103954242A - Overhead-power-transmission-line sag online monitoring method based on UWB ranging technology - Google Patents

Abstract

The invention discloses an overhead-power-transmission-line sag online monitoring method based on a UWB ranging technology. The method includes the following steps: step1: selecting a position to install a UWB ranging device; step2. the UWB device performing ranging; step3. processing measured data and performing sag calculation. The method has the advantages of being high in measurement precision and great in reliability.

Description

Overhead transmission line sag on-line monitoring method based on UWB ranging technology

Technical field

The present invention relates to a kind of on-line monitoring technique, particularly a kind of overhead transmission line sag on-line monitoring method based on UWB ranging technology.

Background technology

Overhead transmission line is being undertaken the important task of delivery of electrical energy, it is the important and indispensable part of electric power networks system, especially as the extra high voltage network of electrical network basic routing line, its safe and reliable stable operational relation is stable to the sound development of national economy and the harmony of society.Overhead transmission line sag is one of leading indicator in line design and operation maintenance, the tightness of overhead transmission line and the height of overhead line structures are determined, its value magnitude relationship is to the safety of whole transmission line of electricity operation, within sag must be controlled in the allowed band of design code.The operating load of transmission line of electricity also has surrounding environment change all may cause the sag of transmission line of electricity to change, and sag is excessive may cause serious potential safety hazard, especially intensive in scissors crossing, the signs of human habitation and cross over greatly location.In addition, the needs that increased due to power load in the last few years, many existing transmission lines of electricity are in order to improve power delivery capabilities, the highest wire operation allowable temperature is brought up to 80 DEG C from 70 DEG C, at this moment line-sag just becomes main restraining factors, need to carry out verification or Real-Time Monitoring to sag, to guarantee circuit operation and by the safety of line balance converter.

Based on the demand, electric power research and run unit have carried out for many years to the research of overhead transmission line sag on-line monitoring both at home and abroad, and gain ground in this respect, proposed actual effective monitoring method, and Development and Production goes out corresponding sag on-Line Monitor Device.At present, the on-line monitoring of sag is mainly realized by measure traverse line stress, inclination angle, temperature or graphical analysis.But these methods are in fact all by indirect means, sag to be measured, consider the measuring error of current related sensor and the precision of transformation model, the sag result obtaining thus often cannot reach higher precision.

Summary of the invention

The shortcoming that the object of the invention is to overcome prior art, with not enough, provides a kind of overhead transmission line sag on-line monitoring method based on UWB ranging technology.The method realizes directly accurate, real-time on-line monitoring to overhead transmission line sag, and precision is high.

Object of the present invention is achieved through the following technical solutions: the overhead transmission line sag on-line monitoring method based on UWB ranging technology, comprises the following steps:

Step 1, Selection of setting UWB distance measuring equipment;

Step 2, UWB device are implemented range finding;

Step 3, the data of measuring are processed and carried out sag calculating.

In described step 1, described UWB distance measuring equipment comprises signal transmitting module, signal receiving module, control module and power module;

One end of described control module is connected with power module, and described signal transmitting module is all connected with the other end of control module with signal receiving module;

Described control module is single-chip microcomputer, is integrated with data frequency collecting unit and AD conversion unit in described single-chip microcomputer.

Described single-chip microcomputer is 89C51 single-chip microcomputer.

Described step 2 comprises the following steps:

Step 2-1, UWB distance measuring equipment carried out time synchronized detection and synchronously adjust before test;

Step 2-2, UWB distance measuring equipment, at interval of the collection of carrying out data for 10 minutes, are realized lasting Real-Time Monitoring to the phase mutual edge distance between monitoring device to be measured, data are sent back in real time to backstage sag processing enter simultaneously, carry out processing and the calculating of data.

In described step 3, the system of equations of carrying out described sag calculating is as follows:

$\left\{\begin{array}{c}{y}_1=f\left(x_1\right)\\ y_2=f\left(x_2\right)\\ y_3=f\left(x_3\right)\\ y_4=f\left(x_4\right)\\ {(x_1-x_2)}^2+{(y_1-y_2)}^2=l_{\mathrm{AB}}^2\\ {(x_1-x_3)}^2+{(y_1-y_3)}^2=l_{\mathrm{AC}}^2\\ {(x_2-x_3)}^2+{(y_2-y_3)}^2=l_{\mathrm{BC}}^2\\ {(x_2-x_4)}^2+{(y_2-y_4)}^2=l_{\mathrm{BD}}^2\\ {(x_3-x_4)}^2+{(y_3-y_4)}^2=l_{\mathrm{CD}}^2\end{array}\right.,$

In formula, (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) represent respectively the coordinate of monitoring device A, monitoring device B, monitoring device C and monitoring device D, and l _aB, l _aC, l _aD, l _bC, l _bD, l _cDrepresent that respectively UWB measures the distance between monitoring device A and monitoring device B, monitoring device A and monitoring device C, monitoring device A and monitoring device D, monitoring device B and monitoring device C, monitoring device B monitoring device D and monitoring device C and the monitoring device D of gained;

The system of equations of being calculated by described sag calculates or numerical value, substitution following formula:

$f_m\≈f_{l/2}=\sqrt{1+{\left(\frac{h}{L_{h=0}}\right)}^2}\frac{{\mathrm{\σ}}_0}{\mathrm{\γ}}(\mathrm{ch}\frac{\mathrm{\γl}}{{2\mathrm{\σ}}_0}-1),$

In formula, f _mthe maximum sag of wire, f _l/2for span central authorities sag, l is span, and h is the discrepancy in elevation between wire two hitch points, σ ₀for the horizontal component of the stress of conductor, γ is the suffered uniform ratio value of carrying of wire,

Wherein, obtain span central authorities sag.

The present invention has following advantage and effect with respect to prior art:

1, by proposing, a kind of measuring accuracy is high, the overhead transmission line sag on-line monitoring system of good reliability in the present invention.Scheme is utilized the UWB ranging technology of high precision, low-power consumption, to on overhead transmission line 4 position range finding, and according to overhead power transmission conducting wire catenary equation, determine wire hanging curve shape, thereby by calculating the actual needed span of engineering central authorities sag.

2, the present invention can realize directly accurate, real-time on-line monitoring to overhead transmission line sag, precision can reach centimetre-sized, and then for the safe distance of circuit, the assessment of state parameter such as the stress of conductor and pitch angle and the dynamic compatibilization of wire provides accurately, reference frame reliably, effectively improve the safe reliability of transmission line of electricity entirety.

3, the present invention selects UWB technology to carry out the on-line monitoring of overhead transmission line sag, UWB technology can realize the measuring accuracy of centimetre-sized in short-distance and medium-distance, and prior art can realize the measuring distance of hundreds of meters, can realize the high-precision real time on-line monitoring of transmission line of electricity sag, power consumption is extremely low simultaneously, alleviate effectively transmission line of electricity power issue and be difficult to solve the pressure bringing, be applicable to transmission line of electricity operation occasion and rugged surroundings.

4, the present invention has adopted corona shielding shell that whole UWB device is enclosed within wherein, has guaranteed that corona drops to the interference of device enough low, improves the reliability of data.

5, the present invention to data carry out smoothly, noise reduction and neural network (ANN) estimate to process, and improves the accuracy of UWB range finding.

6, the present invention has good market popularization value: nowadays, excessive or the too small harm causing of overhead transmission line sag becomes increasingly conspicuous, realize the real time on-line monitoring to sag, be extremely important for the assessment of circuit running status and the dynamic compatibilization of wire.This programme adopts UWB technology to carry out real time on-line monitoring to overhead transmission line sag, and monitoring system precision is high, can reach centimetre-sized, and low in energy consumption, is applicable to transmission line of electricity running environment.If this scheme is extensively promoted, will provide strong help for Regulation and traffic department, grasp in time transmission line of electricity running status, rationally in time arrange line upkeep and operation plan, ensure safe, stable, the reliability service of whole electric system, fully excavate the potential transport capacity of transmission line of electricity simultaneously, realize the dynamic compatibilization of circuit.

Brief description of the drawings

Fig. 1 is the force analysis figure of not contour suspension point wire.

Fig. 2 is several sag schematic diagram of overhead transmission line.

Fig. 3 is UWB one way range finding schematic diagram.

Fig. 4 is the overhead transmission line sag on-line monitoring process flow diagram based on UWB ranging technology.

Fig. 5 is the overhead transmission line sag on-line monitoring system figure based on UWB ranging technology.

Embodiment

Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited to this.

Embodiment

The concrete implementation step of overhead transmission line sag on-line monitoring method based on UWB ranging technology is as shown in Figure 4:

(1) Selection of setting of UWB distance measuring equipment.

UWB distance measuring equipment is mainly made up of signal transmitting module, signal receiving module, control module and power module, there is two-way interactive function, can realize range finding and the communication each other of multiple monitoring devices, simultaneously owing to adopting unique ultra-wideband pulse radiofrequency signal mechanism, even under the environment of height multipath and high reflection, point-to-point distance accuracy also can be up to centimetre-sized.Device is limited to the factors such as device volume and adopts wire induction energy fetching power supply, and is equipped with accumulator and is regulated electric energy, and can the long-time stable power-supplying of implement device.Device is due in hyperbaric environment, corona discharge will produce potential adverse effect to its signal receiving/transmission device, thereby need the corona shielding shell that design outline is smooth and material is light, in order to whole UWB device is enclosed within wherein, to guarantee that corona drops to enough low to the interference of device.

For the hanging curve that makes to be obtained by four monitoring devices accurate as far as possible, UWB distance measuring equipment should be installed on the position that wire radian is larger as far as possible, as the low hitch point side of not contour suspension point pole line, consider the convenience of UWB distance accuracy and installation, the reconnaissance of UWB distance measuring equipment is arranged and is installed as shown in Figure 5 simultaneously.Monitoring device A is installed on wire hitch point place, and these 3 monitoring devices of monitoring device B, monitoring device C and monitoring device D distribute and come successively, and each monitoring device spacing is unsuitable too small, also unsuitable excessive, and the selected mutual spacing of this programme is 25m.

(2) UWB device is implemented range finding.

UWB distance measuring equipment carried out time synchronized and detects and synchronously adjust before test, so that 4 monitoring devices have common clock.

UWB distance measuring equipment, at interval of the collection of carrying out data for 10 minutes, is realized continual Real-Time Monitoring to the phase mutual edge distance between A, B, C, tetra-monitoring devices of D, data is sent back in real time to backstage sag processing enter simultaneously, carries out the processing of data and calculates.

(3) processing of data and sag calculate.

Be subject to the impact of external environment condition, as multipath, catadioptric, noise etc., pass back between the data on backstage and actual value and have deviation, need to carry out smoothly data, noise reduction and neural network (ANN) estimate to process, to improve the degree of accuracy of range finding.

Data after treatment, are calculated according to system of equations (5) and formula (1), consider that between A, D, distance is larger, range error may be poor, and in (5), have redundant equation, and therefore can remove the distance computing formula between A, D, be able to lower system of equations (6):

$\left\{\begin{array}{c}{y}_1=f\left(x_1\right)\\ y_2=f\left(x_2\right)\\ y_3=f\left(x_3\right)\\ y_4=f\left(x_4\right)\\ {(x_1-x_2)}^2+{(y_1-y_2)}^2=l_{\mathrm{AB}}^2\\ {(x_1-x_3)}^2+{(y_1-y_3)}^2=l_{\mathrm{AC}}^2\\ {(x_2-x_3)}^2+{(y_2-y_3)}^2=l_{\mathrm{BC}}^2\\ {(x_2-x_4)}^2+{(y_2-y_4)}^2=l_{\mathrm{BD}}^2\\ {(x_3-x_4)}^2+{(y_3-y_4)}^2=l_{\mathrm{CD}}^2\end{array}\right.,---\left(6\right)$

Can be calculated by system of equations (6) (or ) numerical value, substitution formula (2) can obtain span central authorities sag, realizes the real time on-line monitoring to overhead transmission line sag.

The ultimate principle of the present embodiment:

1, overhead transmission line fundamental equation:

(1) transmission pressure catenary equation:

In the mechanics study of overhead power transmission conducting wire, conventionally ignore the rigidity of wire and look for flexible chain, think that wire is subject to evenly load simultaneously, wire just can calculate with catenary equation, parabolic equation or flat parabolic equation like this.For reducing error, this programme adopts the highest catenary equation of precision.

As shown in Figure 1, be the force analysis figure of not contour suspension point pole line, and suppose that wire is subject to evenly load γ effect, wherein, l is span, and h is the discrepancy in elevation between A, B two hitch points, σ _xfor the stress of any point on wire, σ ₀for σ _xhorizontal component (everywhere all equate), γ is the suffered uniform ratio value of carrying of wire, sets up coordinate system, utilizes catenary equation, can try to achieve wire hanging curve equation:

$y=f\left(x\right)=\frac{h}{L_{h=0}}\left[\frac{{2\mathrm{\σ}}_0}{\mathrm{\γ}}\mathrm{sh}\frac{\mathrm{\γx}}{{2\mathrm{\σ}}_0}\mathrm{ch}\frac{\mathrm{\γ}(l-x)}{{2\mathrm{\σ}}_0}\right]-\sqrt{1+{\left(\frac{h}{L_{h=0}}\right)}^2}\left[\frac{{2\mathrm{\σ}}_0}{\mathrm{\γ}}\mathrm{sh}\frac{\mathrm{\γx}}{{2\mathrm{\σ}}_0}\mathrm{sh}\frac{\mathrm{\γ}(l-x)}{{2\mathrm{\σ}}_0}\right],---\left(1\right)$

Wherein, $L_{h=0}=\frac{{2\mathrm{\σ}}_0}{\mathrm{\γ}}\mathrm{sh}\frac{\mathrm{\γl}}{{2\mathrm{\σ}}_0}.$

(2) sag formula:

On pole line, the sag of any point refers to the vertical distance of this point apart from two suspension point lines.As shown in Figure 2, be several sag schematic diagram of overhead transmission line, wherein, two hitch points that A, B are wire, f _xfor the sag at any point place on aerial condutor, f ₀for wire minimum point sag, f _l/2for span central authorities sag, and f _mit is the maximum sag of wire.

The minimum point of pole line may be positioned at outside span, therefore calculates minimum point sag sometimes without practical significance, so the sag of common indication refers to the maximum sag of pole line.And span central authorities sag and maximum sag are very approaching, generally differ far less than 1cm, it has been generally acknowledged that maximum sag is positioned at span central authorities.In engineering, often utilize span central authorities sag to assess line status.

Sag formula:

$f_m\≈f_{l/2}=\sqrt{1+{\left(\frac{h}{L_{h=0}}\right)}^2}\frac{{\mathrm{\σ}}_0}{\mathrm{\γ}}(\mathrm{ch}\frac{\mathrm{\γl}}{{2\mathrm{\σ}}_0}-1),---\left(2\right)$

2, UWB ranging technology:

UWB (Ultra Wideband) is a kind of carrierfree communication technology, utilizes the non-sinusoidal wave burst pulse transmission data of nanosecond to Microsecond grade, and its shared spectral range is very wide, can be from several Hz to number GHz.According to the FCC(Federal Communications Commission of US Federal Communication Committee) regulation, the frequency range that the bandwidth frequency of the 7.5GHz between from 3.1GHz to 10.6GHz is used for UWB.

UWB can realize the measuring accuracy of centimetre-sized in short-distance and medium-distance, and prior art can realize the measuring distance of hundreds of meters, and power consumption is extremely low simultaneously.Specify according to FCC, in UWB bandwidth, the emissive power of UWB signal is less than 0.56mW, and its emissive power density will be lower than-41.3dBm/MHz (corrected power is 75nW/MHz), and in the time realizing same transfer rate, UWB power consumption is only the 1/10-1/100 of conventional art.Without charge power supply in the situation that, supplying cell also can have the serviceable life that reaches the several years like this.Overhead transmission line is throughout the year among barren hill, running environment is extremely severe, and power supply is difficult to solve, and UWB technology very little power consumption is applied to line-sag on-line monitoring, can rely on merely battery just can maintain monitoring device and work long hours, this will solve power supply problem effectively.

UWB distance-finding method has two kinds: received signal strength method (RSSI) and method time of arrival (TOA).RSSI precision is low, only limits to coarse range finding, and this programme will adopt the higher TOA of precision.TOA comprises again round trip range finding (TWR) and one way range finding (OWR).TWR is applicable to not have between monitoring device the situation of common clock, and OWR uses in the situation that having common clock between monitoring device.OWR ultimate principle is as follows:

As shown in Figure 3, A is with reference to monitoring device, and B is object monitoring device, now measures the distance between A, B monitoring device.Before range finding, monitoring device A, B are synchronously detected and synchronously adjust, monitoring device A is at T ₀moment sends a signal to monitoring device B, and monitoring device B is at T ₁moment is received signal, and the distance between monitoring device A, B can be obtained by following formula:

T _OF=T ₁-T ₀， （3）

d _AB=T _OF·c， （4）

3, sag on-line monitoring ultimate principle:

Supposing has four some A (x on overhead transmission line hanging curve ₁, y ₁), B (x ₂, y ₂), C (x ₃, y ₃), D (x ₄, y ₄), each point all meets formula (1).Phase mutual edge distance l between known each point simultaneously _aB, l _aC, l _aD, l _bC, l _bD, l _cD, set up by following system of equations:

$\left\{\begin{array}{c}{y}_1=f\left(x_1\right)\\ y_2=f\left(x_2\right)\\ y_3=f\left(x_3\right)\\ y_4=f\left(x_4\right)\\ (x_1-x_2)2^{}+{(y_1-y_2)}^2=l_{\mathrm{AB}}^2\\ (x_1-x_3)2^{}+{(y_1-y_3)}^2=l_{\mathrm{AC}}^2\\ (x_1-x_4)2^{}+{(y_1-y_4)}^2=l_{\mathrm{AD}}^2\\ {(x_2-x_3)}^2+{(y_2-y_3)}^2=l_{\mathrm{BC}}^2\\ {(x_2-x_4)}^2+{(y_2-y_4)}^2=l_{\mathrm{BD}}^2\\ (x_3-x_4)2^{}+{(y_3-y_4)}^2=l_{\mathrm{CD}}^2\end{array}\right.,---\left(5\right)$

In formula (1), unknown parameter only has (or ), other parameters are known in the time of line design.Therefore, in system of equations (5), have altogether 9 unknown numbers, and equation has 10, according to the uniqueness of engineering actual suspension curve, system of equations has solution, and only needs wherein 9 equations can obtain each unknown parameter.

Above-described embodiment is preferably embodiment of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under Spirit Essence of the present invention and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection scope of the present invention.

Claims (5)

1. the overhead transmission line sag on-line monitoring method based on UWB ranging technology, is characterized in that, comprises the following steps:

Step 1, Selection of setting UWB distance measuring equipment;

Step 2, UWB device are implemented range finding;

Step 3, the data of measuring are processed and carried out sag calculating.

2. the overhead transmission line sag on-line monitoring method based on UWB ranging technology according to claim 1, is characterized in that, in step 1, described UWB distance measuring equipment comprises signal transmitting module, signal receiving module, control module and power module;

One end of described control module is connected with power module, and described signal transmitting module is all connected with the other end of control module with signal receiving module;

Described control module is single-chip microcomputer, is integrated with data frequency collecting unit and AD conversion unit in described single-chip microcomputer.

3. the overhead transmission line sag on-line monitoring method based on UWB ranging technology according to claim 2, is characterized in that, described single-chip microcomputer is 89C51 single-chip microcomputer.

4. the overhead transmission line sag on-line monitoring method based on UWB ranging technology according to claim 1, is characterized in that, described step 2 comprises the following steps:

Step 2-1, UWB distance measuring equipment carried out time synchronized detection and synchronously adjust before test;

Step 2-2, UWB distance measuring equipment, at interval of the collection of carrying out data for 10 minutes, are realized lasting Real-Time Monitoring to the phase mutual edge distance between monitoring device to be measured, data are sent back in real time to backstage sag processing enter simultaneously, carry out processing and the calculating of data.

5. the overhead transmission line sag on-line monitoring method based on UWB ranging technology according to claim 1, is characterized in that, in step 3, the system of equations of carrying out described sag calculating is as follows:

$\left\{\begin{array}{c}{y}_1=f\left(x_1\right)\\ y_2=f\left(x_2\right)\\ y_3=f\left(x_3\right)\\ y_4=f\left(x_4\right)\\ {(x_1-x_2)}^2+{(y_1-y_2)}^2=l_{\mathrm{AB}}^2\\ {(x_1-x_3)}^2+{(y_1-y_3)}^2=l_{\mathrm{AC}}^2\\ {(x_2-x_3)}^2+{(y_2-y_3)}^2=l_{\mathrm{BC}}^2\\ {(x_2-x_4)}^2+{(y_2-y_4)}^2=l_{\mathrm{BD}}^2\\ {(x_3-x_4)}^2+{(y_3-y_4)}^2=l_{\mathrm{CD}}^2\end{array}\right.,$

In formula, (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) represent respectively the coordinate of monitoring device A, monitoring device B, monitoring device C and monitoring device D, and l _aB, l _aC, l _aD, l _bC, l _bD, l _cDrepresent that respectively UWB measures the distance between monitoring device A and monitoring device B, monitoring device A and monitoring device C, monitoring device A and monitoring device D, monitoring device B and monitoring device C, monitoring device B monitoring device D and monitoring device C and the monitoring device D of gained;

The system of equations of being calculated by described sag calculates or numerical value, substitution following formula:

$f_m\≈f_{l/2}=\sqrt{1+{\left(\frac{h}{L_{h=0}}\right)}^2}\frac{{\mathrm{\σ}}_0}{\mathrm{\γ}}(\mathrm{ch}\frac{\mathrm{\γl}}{{2\mathrm{\σ}}_0}-1),$

In formula, f _mthe maximum sag of wire, f _l/2for span central authorities sag, l is span, and h is the discrepancy in elevation between wire two hitch points, σ ₀for the horizontal component of the stress of conductor, _γfor the suffered uniform ratio value of carrying of wire,

Wherein, obtain span central authorities sag.